Here's why:
* Thesis statement as a roadmap: The thesis statement acts as a guide for the reader, outlining the main argument or point of the paragraph or essay. Placing it at the beginning helps the reader understand what to expect.
* Supporting evidence: The rest of the paragraph or essay provides evidence and reasoning to support the thesis statement.
However, there are some exceptions:
* A surprising conclusion: A thesis statement might be presented at the end of a paragraph if the author wants to create a sense of surprise or build suspense.
* A summary paragraph: In a summary paragraph, the thesis statement might be reiterated at the end to reinforce the main point.
In short, a thesis statement is typically placed at the beginning of a paragraph or at the end of the introduction to provide a clear roadmap for the reader.